What rig to go for?

[Arty64]

EVGA nvidia GeForce GTX 980 SuperClocked
Intel Core i7-5820K
Gigabyte GA-X99-Gaming 5 Motherboard 
Crucial 8GB DDR4 
WD Green 2TB SATA III Hard Drive (Storage)
SanDisk 64GB SSD SATA Drive (Boot Drive)
XFX xxx 750w modular PSU
Corsair Hydro H80i Cooler

-or-

EVGA nvidia GeForce GTX 980 SuperClocked
Intel Core i7-4790k
MSI Z97 Gaming 5 Motherboard 
G.skill ripjaws X 8GB
WD Green 2TB SATA III Hard Drive (Storage)
SanDisk 64GB SSD SATA Drive (Boot Drive)
XFX xxx 750w modular PSU
Corsair Hydro H80i Cooler

Will I see any performance decrease if I don't opt for the haswell-e build?

 

[esco_sid]

in games most likely you will see better performance on the 4790k due to its higher clock rate and most games only using 4 cores. Also what is your budget ? i might be able to do a better build for you if you want.

 

[zeyuanfu]

I would say the first one (X99) as it'll last longer than the other build.

 

[MasterDell]

Tuff choice. But I would go with the first build. Much more future proof with that 5820k. People seem to think that 4 cores is ALL that games are using..
http://www.tomshardware.com/reviews/intel-core-i7-5960x-haswell-e-cpu,3918-6.html
http://www.tomshardware.com/reviews/intel-core-i7-5960x-haswell-e-cpu,3918-6.html

5820k wins in every scenario except one. And thats right now.. Wait till the future